Please refer to FIG. 1 which schematically shows the appearance of a receptacle, which is suitable to be used outdoors, for example, to extend power supply due to the material property thereof. As shown, the socket 101 of the receptacle 10 is provided for inserting and fitting therein a power plug 11. By the electric contact of the metal pins 111, 112 and 113 of the power plug 11 with the conductive terminals (not shown) in the socket 101, power can be extensively supplied to a distant electrical appliance, especially an outdoor appliance. For an outdoor receptacle, a thermally stable physical property is required because the surrounding temperature that the receptacle is subject to may vary from day to day up to tens of degrees. A material conventionally used for making a general receptacle is polyvinyl chloride (PVC). PVC, however, is not a good material for an outdoor receptacle due to its relatively high temperature sensitivity in volume, i.e. relatively significant expansion/shrinkage effect with temperature. The significant change in socket volume is likely to obstruct the plugging/unplugging operation of the power plug or cause poor contact between the power plug and the receptacle. Therefore, composite materials and a specific assembling manner have been used to produce an outdoor receptacle.
The composite receptacle includes an inner body and a wrapping portion The inner body is made of an insulating material of relatively low temperature sensitivity, for example a kind of engineering plastic such as polycarbonate, and then partially sealed by the wrapping portion made of a general insulating material such as PVC, leaving the socket face exposed. By this way, even in a chilly climate down to -20.degree. C., the connector can still work well.
For a conventional composite receptacle, the inner body consists of a socket portion and a conductive terminal portion. The conductive terminal portion is located in the socket portion for clamping metal pins of a plug therebetween when the plug is inserted into the socket portion. As shown in FIG. 2 which schematically shows the conductive terminal portion of a conventional composite receptacle, the conductive terminal portion 21 generally includes two sets of elastic metal pieces 211 and 212 for clamping therebetween two metal pins of the plug, respectively, and one conductive sleeve 213 for optionally receiving therein a ground pin of the plug. In order to guide the metal pins of the plug into the passages 214 of the two sets of metal pieces 211 and 212 smoothly, the front end of each metal piece is properly bent to make the opening 215 of each of the passages 214 have a funnel shape.
Unfortunately, owing to the relatively large passage opening, the positioning of the conductive terminal portion into the socket portion is difficult so that the socket portion of the conventional inner body has to be divided as two parts, i.e. a seat part for receiving the metal pieces and a cover part for securing the metal pieces in the seat part, as shown in FIG. 3 which schematically shows the socket portion of the conventional composite receptacle having the conductive terminal portion of FIG. 2.
As shown, the two sets of metal pieces 211 and 212 and the conductive sleeve 213 of the conductive terminal portion are placed downwards into two side trenches 311 and 312 and a top trench 313 of the seat part 31 from the top of the trenches, respectively, with the bent front ends of the metal pieces protruding from the front surface of the seat part 31. After the conductive terminal portion is settled in the seat part, the cover part 32 is combined with the seat part 31 having positioned therein the conductive terminal portion by inserting the seat part 31 into the cover part 32 from the rear surface of the cover part 32 to form the inner body. Afterwards, the insulating material such as PVC, as mentioned above, is injection molded onto the assembled inner body to form the wrapping portion. By this way, the outdoor receptacle can be obtained.
From the above description, it is understood that the assembling process of the conventional outdoor receptacle is relatively complicated and the manufacturing cost is relatively high owing to the division of the socket portion as two separate parts. By the way, it is also a problem that the manufacturing accuracy should be highly required in order to perfectly combine the two separate parts.